Processes of this general type are well-known. Typically, the particulate media is a resin which takes up one of more components from the fluid by ion exchange. Ion exchange processes are used for softening water by passing the water through a bed of cation exchange resin particles selected to remove scaling components such as calcium and magnesium. The resin bed is periodically regenerated by passing a suitable regenerant solution through the bed.
Processes of the general type referred to above also have application in the purification or extraction of chemicals from liquids. Gasses may also be treated by this type of process.